Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
  • B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
  • B60T13/24—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being gaseous
  • B60T13/46—Vacuum systems
  • B60T13/52—Vacuum systems indirect, i.e. vacuum booster units
  • B60T13/567—Vacuum systems indirect, i.e. vacuum booster units characterised by constructional features of the casing or by its strengthening or mounting arrangements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
  • B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
  • B60T13/24—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being gaseous
  • B60T13/46—Vacuum systems
  • B60T13/52—Vacuum systems indirect, i.e. vacuum booster units
  • B60T13/567—Vacuum systems indirect, i.e. vacuum booster units characterised by constructional features of the casing or by its strengthening or mounting arrangements
  • B60T13/5675—Supportstruts

Definitions

• the present invention relates to a braking device for a motor vehicle comprising a fixing support and a pneumatic brake booster fixed in operation to the support, the booster itself comprising a rigid casing at least formed of a front shell and a rear shell which is adjacent to the support in operation, this envelope being reinforced at least by a spacer and delimiting an internal volume in which two chambers are separated from each other by means of a movable partition, the spacer passing through the front shell, the movable partition, and the rear shell, and comprising a screw of which a rear end carries a thread capable of being screwed into the support, and of which a front end, external with respect to the front shell, forms a clamping head capable of exerting support on the front shell.
• the embodiment illustrated in this previous document requires, in order to guide the screw of the spacer, to have recourse to a tube which is also an integral part of the spacer.
• the invention is situated in this context and aims to overcome this constraint.
• the device of the invention is essentially characterized in that the screw itself passes directly through the front shell, the movable partition, and the rear shell and has, between its two ends, an essentially cylindrical intermediate section, in that this intermediate section carries a first stop, internal with respect to the front shell and distant from the clamping head, in that the rear shell carries a sleeve in which the rear end of the screw is engaged and freely sliding, in that the sleeve has a length suitable for preventing the rear end of the screw from escaping from this sleeve, and in that the first stop is placed, on the intermediate section of the screw, in a position suitable for allowing the thread not to protrude out of the sleeve before the servomotor is fixed to the support.
• the intermediate section of the screw advantageously carries a second stop intended to come into abutment against a front face of the sleeve when the screw is screwed into the support, the tightening head then coming to bear on the front shell, on which it exerts a stress of predetermined compression.
• the device of the invention also preferably comprises a first seal for sealing the crossing of the front shell by the screw between the clamping head and the first stop, and a second seal for sealing the crossing of the sleeve by the screw between the second stop and the thread.
• the movable partition comprises a flexible membrane
• this membrane can for example form a bellows surrounding a part of the intermediate section of the screw and terminated by a lip sealingly supported on this intermediate section.
• FIG. 1 is a partial sectional view of a device according to the invention, observed before the servomotor is fixed to the support;
• FIG. 2 is a partial sectional view of a device according to the invention, observed at the time when the booster is positioned on the support for its subsequent fixing;
• FIG. 3 is a partial sectional view of a device according to the invention, observed after the servomotor has been fixed on the support.
• the invention relates to a braking device for a motor vehicle essentially comprising a fixing support 1 and a pneumatic brake booster 2, fixed in operation to the support 1.
• the booster 2 to which the invention applies itself comprises, in known manner, a rigid casing 3 generally formed by a front shell 31 and a rear shell 32, the latter being adjacent to the support 1 when the booster is in operation and fixed to support 1.
• the envelope 3 is reinforced by one or more spacers such as 4, and possibly by additional reinforcements such as the plate 9.
• This envelope 3 delimits an internal volume in which two chambers 33, 34 are separated from each other by means of a movable partition 5, which generally comprises a flexible membrane 50.
• the spacer 4 passes through the front shell 31, the movable partition 5, and the rear shell 32, and comprises a screw 40, a rear end 42 of which carries a thread 421 capable of being screwed into the support 1, and of which a front end 41, external with respect to the front shell 31, forms a clamping head 41 1 capable of exerting support on the front shell 31.
• the screw 40 itself passes directly through the front shell 31, the movable partition 5, and the rear shell 32 and has for this purpose, between its two ends 41, 42, an intermediate section 43 which is essentially cylindrical.
• this intermediate section 43 carries a front stop 61, disposed in the internal volume 33, 34 which delimits the envelope 3, and distant from the clamping head 41 1.
• the rear shell 32 carries a rigid sleeve 7, for example crimped on the rear shell, and in which the rear end 42 of the screw 40 is engaged and freely sliding.
• the position of the front stop 61 on the intermediate section 43 of the screw is chosen, depending on the length of the screw and the thickness of the actuator, so that the thread 421 of the screw 40 may not protrude from the sleeve 7, and therefore from the booster 2, before the latter is fixed to the support, as shown in FIGS. 1 and 2.
• the sleeve 7 is given a length L such that the rear end 42 of the screw 40 cannot escape from the sleeve 7, despite the possibility which is given by construction, the screw 40 slides with respect to the booster 2 as long as the latter is not fixed to the support 1.
• a simple way of satisfying these conditions therefore consists, for example, in placing the front stop 61 so that, when the screw 40 is pulled as far as possible out of the envelope 3 from the side of its head 41 1 as shown in FIGS. 1 and 2, the rear end 42 of the screw is flush with the rear shell 32 of the casing 3 and that the sleeve, in this position of the screw, retains the rear end 42 of the latter.
• the distance separating the front stop 61 from the rear end 42 of the screw must be greater than the distance separating the front face 71 of the sleeve 7 from the support 91 of the front stop 61 on the inside of the front shell 31.
• the distance separating the front stop 61 from the thread 421, including the thickness of this stop 61 and the length of the thread 421, must be at most equal to the distance separating the support 1 from the support 91 of the front stop 61 on the inside of the front shell 31.
• the front stop 61 is for example constituted by a split elastic ring, which is inserted in a circular groove 44 of the intermediate section 43 of the screw 40 once the screw 40 has been engaged in the front shell 31, and before the front shells 31 and rear 32 are crimped on one another, or joined to one another by any other means.
• the intermediate section 43 of the screw 40 may also include a second stop 62, for example formed by a circular rib of the screw 40, and intended to come into abutment against the front face 71 of the sleeve 7 when the screw 40 is screwed into the support 1, and thus limit the screwing of the screw 40.
• a second stop 62 for example formed by a circular rib of the screw 40, and intended to come into abutment against the front face 71 of the sleeve 7 when the screw 40 is screwed into the support 1, and thus limit the screwing of the screw 40.
• the distance separating the second stop 62 from the internal support 412 of the clamping head 41 1, including the thickness of this stop 62, is less than the distance separating, before the actuator is fixed, the front face 71 of the sleeve 7 of the zone Z of the front shell 31 on which the clamping head 411 comes to bear, so that the clamping head 411 comes to bear on the front shell 31 before the rear stop 62 comes to bear on the front face 71 of the sleeve 7, the screw 40 thus exerting a predetermined compression stress on the casing of the booster after it has been fixed on the support.
• a first seal 81 for example housed in a groove in the reinforcement plate 9, is advantageously provided between the clamping head 411 and the first stop 61 to make the crossing of the front shell 31 by the screw 40 completely sealed.
• a second seal 82 for example housed in a groove of the screw between the second stop 62 and the thread 421 and closing, in operation, the sleeve 7, is preferably provided to make the passage through the sleeve 7 by screw 40.
• the movable partition 5 comprises a flexible membrane 50 and a rigid skirt 59
• this skirt is pierced with an orifice 52 to let pass the screw 40
• the membrane 50 forms a bellows 51 which surrounds part of the intermediate section 43 of the screw 40 and which is terminated by a lip 51 1 in leaktight support on this intermediate section 43.
• the device of the invention may include several screws such as the screw 40 illustrated in the figures, and, in practice, will preferably include two screws of this type.

Landscapes

• Engineering & Computer Science (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Braking Systems And Boosters (AREA)
• Braking Arrangements (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9525608

Family Applications (1)

Country Status (8)

Families Citing this family (6)

Citations (3)

Family Cites Families (10)

• 1998
  • 1998-04-24 FR FR9805116A patent/FR2777850B1/fr not_active Expired - Fee Related
• 1999
  • 1999-04-15 ES ES99913417T patent/ES2194450T3/es not_active Expired - Lifetime
  • 1999-04-15 KR KR1020007011337A patent/KR20010034774A/ko not_active Application Discontinuation
  • 1999-04-15 WO PCT/FR1999/000884 patent/WO1999055568A1/fr not_active Application Discontinuation
  • 1999-04-15 US US09/297,966 patent/US6186050B1/en not_active Expired - Lifetime
  • 1999-04-15 DE DE69905703T patent/DE69905703T2/de not_active Expired - Lifetime
  • 1999-04-15 JP JP2000545739A patent/JP4570248B2/ja not_active Expired - Fee Related
  • 1999-04-15 EP EP99913417A patent/EP1071597B1/fr not_active Expired - Lifetime

Patent Citations (3)

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